5 STARLING REVIEW Ernest Starling and ‘Hormones’: an historical commentary .. John Henderson Department of Physiology, Department of Basic Medical Science, St Georges Hospital Medical School, Tooting, London SW17 0RE, UK (Requests for offprints should be addressed to J Henderson; Email: [email protected]) Abstract One hundred years ago Ernest Starling (1866–1927), the nineteenth century, attempts to trace the growth of almost surreptitiously, slipped the word ‘hormone’ into the ideas in endocrinology up to this important moment. English language. This review, beginning in the middle of Journal of Endocrinology (2005) 184, 5–10 Introduction that he is given the credit for ‘internal secretion’. Unfor- tunately, the rest of the world borrowed the expression, There is no magic date from which to begin a survey of and used it for the passage of any molecule (including endocrinology, for man has made use of endocrinological carbon dioxide) from tissues into blood (see information on principles from time immemorial. Fuller Albright (1943) Schäfer below). observed ‘The earliest beginnings of endocrinology had as Disordered function of the blood-glands was first de- their raisons d’être such ends as the procurement of a form scribed from careful clinical observation. Thus, Thomas of man-power safe for the harem, the salvaging of a male Addison (1855) described a syndrome that he associated soprano voice for the choir, and the increased palatability with disease of the suprarenal glands, with the patients that a rooster attains when he turns into a capon.’ The suffering from weakness, vomiting and skin pigmentation. middle of the nineteenth century finds an awareness of When the London Medico-Chirurgical Society would not glands that had no ducts, glands that communicated only publish his findings in its Transactions, poor Addison – a with blood vessels (Blütdruesen; blood-glands). But it was manic depressive – committed suicide. The Anglo- a purely anatomical description, and most authors of French-American physician, Charles Brown-Séquard (of the time included the thyroid, lymph nodes, thymus, whom more later) demonstrated that removal of the suprarenals and spleen in the collection of blood-glands. adrenals in experimental animals was invariably fatal; no With a little imagination, it was possible to find a function distinction was drawn between adrenal cortex and medulla for them: W B Carpenter, in his ‘Cyclopedia of Anatomy at that time. and Physiology’ (1852), wrote that ‘the products [of the In the 1870s, syndromes associated with over or under glands] destined to be restored to the circulating current, activity of the thyroid gland were described and a host of apparently in a state of more complete adaptiveness to the eponyms came into being, describing many aspects of wants of the nutritive function . glands concerned in human thyroid disease. But biochemistry hardly existed, so the assimilation of the materials that are destined to be no chemical rationale could be offered for either adrenal or converted into organized tissues, instead of being the thyroid disorders. instrument of the matters which result from the disinte- Brown-Séquard (who was simultaneously on the staff of gration or decay of the tissues.’ This seems to be a sort of the Hospital for Nervous Diseases at Queen Square and a intuitive groping towards an endocrine control of inter- Professor of Medicine at the College de France) proposed mediary metabolism. that testicular extracts had a rejuvenating effect in man, for Claude Bernard, in 1855, is usually held responsible for he had tried them on himself (he was 72 at the time). He the term ‘internal secretion’, a phrase that he used to went on to claim that almost any sort of illness would describe the release of glucose from liver glycogen. It is respond to testicular extracts; moreover, every organ in the likely that the phrase existed in the French and German body produced an agent with a possible therapeutic use. literature long before Bernard (Medvei 1982), but An article about him in the British Medical Journal was Bernard’s demonstration was so convincing and clear-cut appropriately called ‘The Pentacle of Rejuvenescence’, Journal of Endocrinology (2005) 184, 5–10 DOI: 10.1677/joe.1.06000 0022–0795/05/0184–005 2005 Society for Endocrinology Printed in Great Britain Online version via http://www.endocrinology-journals.org Downloaded from Bioscientifica.com at 10/03/2021 03:50:45PM via free access 6 J HENDERSON · Starling and hormones Figure 1 Ernest Starling photographed in his office in UCL around 1921. The three-piece suit and the wing collar were his uniform throughout the 1920s. ‘Pentacle’ being a symbol used in magic (Annotation Journal in 1893: ‘The great movement in therapeutics as (anonymous) 1889). But Brown-Séquard’s bizarre ideas regards the organic liquid extracts has its origin in the were made respectable by giving them a title, ‘organo- experiments which I made on myself in 1889, experiments therapy’, and it seemed to be welcomed by physicians which were at first so completely misunderstood’[!] on both sides of the Atlantic. In 1891, Victor Horsley, a (Brown-Séquard 1893). In the market place, organo- pioneer neurosurgeon, and his pupil, George Murray, therapy extracts borrowed a ride alongside more respect- showed that hypothyroid (myxoedematous) patients could able animal products, such as thyroid extracts, and tetanus be successfully treated with thyroid extracts – a landmark and diphtheria antitoxins. Fortunately, by the turn of the in real endocrinology. Brown–Séquard saw this as a century organotherapy had virtually disappeared (Borell vindication of his ideas. He wrote in the British Medical 1976). Journal of Endocrinology (2005) 184, 5–10 www.endocrinology-journals.org Downloaded from Bioscientifica.com at 10/03/2021 03:50:45PM via free access Starling and hormones · J HENDERSON 7 It is possible that Brown-Séquard’s obsession with tissue The arrival of Starling extracts actually had some benefit. Thus in 1893, George Oliver, a spa physician working in Harrogate, was making In 1899, Schäfer left UCL for the chair of physiology at extracts of adrenals, believing that they might raise blood Edinburgh. It is not clear why he did this, although it pressure and be of use in patients with low blood pressure. might be relevant that the change more than doubled his (It is not clear why Oliver believed there to be a connec- salary. The new professor at UCL was Ernest Starling, tion between the adrenals and blood pressure – an impor- then aged 32. Starling had just been elected to the Royal tant gap in the story.) He gave some extract to his own son, Society for his work on the formation of lymph; he showed and using a device of his own invention (an ‘arteriometer’) that the outward hydrostatic forces in the capillary were showed that his son’s brachial artery narrowed under the opposed by inward osmotic forces brought about by influence of the injection. Unfortunately, Oliver did not plasma proteins (‘Starling’s Principle’). Figure 1 is a formal have a blood pressure measurer, so he took some of his portrait of him, taken some years after the research extract to Edward Schäfer, Professor of Physiology at described here. University College, London (UCL). We have a descrip- Starling and his brother-in-law, William Bayliss, were tion of the meeting from Henry Dale: ‘Oliver went to tell compulsive experimenters. At UCL, in the first years of Professor Schäfer what he thought he had observed, and the century, they investigated the innervation and move- found him engaged in an experiment in which the blood ments of the small intestine, and made the first serious pressure of a dog was being recorded: found him, not descriptions of peristalsis. While investigating the innerva- unnaturally, incredulous about Oliver’s story and very tion of the pancreas and duodenum (Bayliss & Starling impatient at the interruption. But Oliver was in no hurry, 1901, 1902) they were repeating Pavlov’s experiments on and urged only that a dose of his adrenal extract, which he the nervous control of the gut (he was awarded a Nobel produced from his pocket, should be injected into a vein Prize for this work in 1904). Pavlov believed that pancre- when Schäfer’s own experiment was finished. And so, just atic secretion was solely controlled by the vagus; when to convince Oliver that it was all nonsense, Schäfer gave acid gastric contents passed into the duodenum, vagal the injection, and then stood amazed to see the mercury afferents in the duodenal wall passed to the brain, and mounting in the manometer ‘til the recording float was vagal efferents returned to the pancreas, stimulating the lifted almost out of the distal limb . .’. (Dale 1948). secretion of pancreatic juice into the duodenum. Bayliss Schäfer was perhaps the first serious laboratory scientist and Starling carefully dissected away all the nerves that to involve himself with the endocrine system. He and accompanied the vessels supplying the pancreas and duo- Oliver studied, in detail, the effects of adrenal extracts on denum. They then put acid into the duodenum, and blood pressure; it was the adrenal medulla (not the cortex) pancreatic secretion occurred in the normal way. So it was that gave rise to the pressor effect. They went on to show possible (but not certain) that some other mechanism was (in 1895; Schäfer 1895) that extracts of the pituitary caused responsible for pancreatic secretion in response to acid in a rise in blood pressure, and thyroid extracts caused a fall. the duodenum. Working on the hypothesis that acid Schäfer was sceptical about clinical observation as a basis caused the release of something from the duodenum into for the science of endocrinology, and had little time for the blood, they scraped some mucosa from the duodenum, Brown-Séquard’s fantasies.